TWO DIFFERENT KINDS OF INTERNAL FRICTION PEAK IN Al-Sn POLYCRYSTALS
Al-Sn 合金中两个不同类型的内耗峰

Two different kinds of internal friction peak located at the high-temperatureside of grain boundary peak(GBP)(denoted as P_1 and P_2 were observed in Al-Sn polycrystals.They are related to the grain boundaries because of their disappearence in Al-Sn singlecrystalline specimens.The peak P_1 occurred in Al-0.008wt-%Sn and Al-0.0135wt-%Snpolycrystals is a process peak.The P_1 which has a decline-growth relation with GBP,occursonly in measurements with descending temperature,and is sensitive to aging and annealing.Theother P_2 in Al-0.067wt-%Sn and Al-O.136wt-%Sn,however,is a stable peak.The P_2 hassomething to do with the size of grains and specimens.The results in this paper show that theP_1 is contributed to those fine grain boundaries non-equilibrium segregated with lots of tin at-oms,and the P_2 is contributed by those coarse grain boundaries containing Al-Sn particles.